Amazing Astrophoto: The Phases of Venus

A montage of Venus from January to May 2012. Credit: Efrain Morales

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Wow! Take a look at how Venus has changed in the night sky the past five months!

“The Planet Venus, The Roman goddess of love and beauty and the closest planet to us — especially now just as it gets closest — will transit across the Sun soon,” said astrophotographer Efrain Morales. “This sequence is a five month transition showing its size continuing to grow and its crescent getting thinner as time progresses.” Venus’ transit of the Sun will be on June 5/6, 2012, depending on your location. This won’t happen again in your lifetime, so don’t miss this opportunity.

Click on the image for a larger version to see all the details. Check out Efrain’s website and Flickr page for more astrophotos.

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Astrophoto: Lovely Crescent Venus by John Chumack

A beautiful crescent Venus on May 14, 2012. Credit: John Chumack.

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Named after the Roman goddess of love and beauty, Venus has never looked more gorgeous! Prolific and accomplished astrophotographer John Chumack captured this shot of a crescent Venus on May 14, 2012 as it moves in for a transit of the Sun. Just 14% of Venus’ face was illuminated, 22 Days before the June 5th Transit of Venus across the Sun. John used a DMK 21AF04 fire-wire Camera, 2x Barlow, & 10″ SCT telescope, and used 950 frames stacked to create this image. Thanks to John for sharing his image; see more of his work at his website, Galactic Images.

Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Venus Transit — There’s an App for That!

Transit of Venus by NASA's TRACE spacecraft Image credit: NASA/LMSAL
Transit of Venus in 2004 by NASA's TRACE spacecraft. Image credit: NASA/LMSAL

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There have been only six Venus transits since the invention of the telescope in the early 17th century. It was not until 1761 that the transit of Venus on June 6th was observed as part of the first ever international scientific observation project, instigated by Edmond Halley. Astronomers across the globe viewed the transit and the differences in their observations were used to triangulate the distance to Venus and, using Kepler’s laws, the distance to the Sun, the other planets and the size of the Solar System. Though the method used has not changed in the 251 years since, the equipment most certainly has.

For this transit, we have technology on our side.

In previous Venus Transits, expeditions were sent out far and wide and the 1761 transit was eventually recorded by 120 individual astronomers from 62 locations across Europe, America, Asia and Africa. They used only the simple telescopes of the day, fitted with dense filters, a pendulum clock to time the transit and quadrants to determine their exact latitude and local time. It is hardly surprising that their observations varied widely. Their calculations put the Sun’s distance between 130 and 158 million kilometres.

Transits happen in pairs. After 121 years a transit occurs followed 8 years later by another, then 105 years pass before the next pair and then the pattern repeats. Prior to the transit of 2004 the most recent transit was in 1882. There were none during the whole of the 20th century! We now approach the last chance to view a transit in our lifetime, the next will not occur until 2117.

Luckily, we’ve got some newly developed technology to help make this the most-observed transit ever!

Astronomers Without Borders are part of the Transit of Venus Project to get as many people around the world to observe the transit and to participate in a collective experiment to measure the Sun’s distance. To this end they have produced the Venus Transit phone app, available to download free for both iTunes and Android. Once downloaded you can start to practice timing the interior contacts of ingress and egress using a simulation of the transit. This is not as easy as it seems, as the black drop effect makes precise timing tricky so practice is definitely recommended. The app will tell you how far out you are so that you can perfect your timing and it will also predict times of contact based on your location together with times of sunrise and sunset.

On the day of the transit, the app will record the exact GPS time and your location, which is sent to the global database. Afterwards you can access your data on the website’s map to edit your entry, and upload descriptions, text, images, or movies and view other entries as well. This transit will be visible over most of the Earth except for parts of West Africa and most of South America, so download, get practicing and become part of a once in a lifetime, global citizen science experiment!

Find out more at Transit of Venus

How the Hubble Telescope Will Look at the Moon to See Venus Transit the Sun

Scientists used the Hubble Space Telescope to look at the Moon to prepare for special observations of the 2012 Venus transit of the Sun. Credit: NASA, ESA, and D. Ehrenreich (Institut de Planetologie et d'Astrophysique de Grenoble (IPAG)/CNRS/Universite Joseph Fourier)

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Venus moving across the face of the Sun, from our vantage point here on Earth, is such a rare event, that astronomers and observatories around the world have been preparing for this year’s Venus Transit, on June 5-6. And one observatory that is literally “around the world,” – the Hubble Space Telescope — is even planning to make observations of this transit event. What, you say? The Hubble telescope can’t look at the Sun – it would fry every component on board! Hubble scientists are being pretty sneaky, if not resourceful so they too can join in the observations.

Since Hubble can’t look at the Sun directly, astronomers are planning to point the telescope at the Moon, using it as a mirror to capture reflected sunlight and isolate the small fraction of the light that passes through Venus’s atmosphere. Imprinted on that small amount of light are the fingerprints of the planet’s atmospheric makeup.

Scientists say these observations will mimic a technique that is already being used to sample the atmospheres of giant planets outside our solar system passing in front of their stars. In the case of the Venus transit observations, astronomers already know the chemical makeup of Venus’s atmosphere, and that it does not show signs of life on the planet. But the Venus transit will be used to test whether this technique will have a chance of detecting the very faint fingerprints of an Earth-like planet, even one that might be habitable for life, outside our solar system that similarly transits its own star.

Venus is an excellent stand in for Earth because of how similar in size and mass it is to our planet.

Several different instruments on Hubble will be used in this special observation. The Advanced Camera for Surveys, Wide Field Camera 3, and Space Telescope Imaging Spectrograph, to view the transit in a range of wavelengths, from ultraviolet to near-infrared light. During the transit, Hubble will snap images and perform spectroscopy, dividing the sunlight into its constituent colors, which could yield information about the makeup of Venus’s atmosphere.

Hubble will observe the Moon for seven hours, before, during, and after the transit so the astronomers can compare the data. Astronomers need the long observation because they are looking for extremely faint spectral signatures. Only 1/100,000th of the sunlight will filter through Venus’s atmosphere and be reflected off the Moon.

Because the astronomers only have one shot at observing the transit, they had to carefully plan how the study would be carried out. Part of their planning included the test observations of the Moon, such as when they took the top image of Tycho Crater.

Hubble will need to be locked onto the same location on the Moon for more than seven hours, the transit’s duration. For roughly 40 minutes of each 96-minute orbit of Hubble around the Earth, the Earth occults Hubble’s view of the Moon. So, during the test observations, the astronomers wanted to make sure they could point Hubble to precisely the same target area.

This is the last time this century sky watchers can view Venus passing in front of the Sun. The next transit won’t happen until 2117. Venus transits occur in pairs, separated by eight years. The last event was witnessed in 2004.

Find more on how you can observe the Venus transit for yourself in this article by Tammy Plotner.

Source: HubbleSite

2012 Venus Transit – The Countdown Is On!

Venus 34 Days Before 2012 Transit - Credit: John Chumack

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Head outside on any clear night this week and you won’t be able to miss brilliant Venus decorating the western horizon. Right now it’s surrounded by a host of bright winter stars like Capella, Betelgeuse, Aldebaran and the Pleiades. But, don’t stop there. Use any type of optical aid and you’ll see the planet is in the crescent phase right now and bigger than Jupiter in apparent size!

There’s a lot of things to know about viewing Venus. Oddly enough, the smaller the phase, the more brightly it shines. If you cannot see its slender form for the glare, simply try wearing sunglasses while using your binoculars… or stacking dark filters, such as green and blue, for the telescope eyepiece. While you’d think that something which sparkles and shines like Venus would be very exciting to see magnified, it’s actually pretty bland. However, don’t let rather ordinary appearances fool you. Behind that “girl next door” exterior is a really radical chick. Beneath the bland clouds runaway greenhouse gases heat things up to 860 degrees Fahrenheit (460 degrees Celsius) and volcanoes rule.

Keep on watching Venus. Right now she’s headed towards Earth and the pinnacle of observing excitement – the Transit. It will continue to grow larger in apparent size and the crescent phase will narrow even more. On June 5 (June 6 in Australia and Asia), it will pass between the Earth and Sun… an event which only happens about twice in a century and won’t happen again until the year 2117!

Venus Transit Sequence 2004 - Credt: John Chumack

The clock is ticking and now is the time to begin your preparations to view the transit of Venus. Do not wait until just a few days before the event to choose a location for your observations. If you do, you might find yourself faced with clouds… an obstruction you hadn’t planned on… getting permission to be in a certain area… or many other things. Knowing exactly where the Sun will be during the transit means a relaxed experience!

As of now, you’re going to find it will be very difficult to locate solar filters for particular telescopes – and waiting any longer may mean not having one at all. Because the transit of Venus is such a rare event, many retailers are carrying special eclipse/transit viewing glasses. They will appear much like the cardboard 3D glasses you get at the movie theatre, but instead of red and blue lenses, they will have either black mylar or Baader filter film. These glasses are safe for solar viewing, but there are a few things you must understand about them. Before you view, please inspect the edges carefully to make sure they are sealed and no sunlight can enter. Even more importantly, do not use them in conjunction with binoculars or a telescope. Eclipse glasses were meant strictly for use with your eyes. Concentrating sunlight with an optical aid and hoping the glasses will be enough to block the Sun’s harmful rays is taking a chance at blinding yourself. Always use approved solar filter material when viewing with telescopes or binoculars and always supervise when children are present.

Venus Transit 2004 - Credit: John Chumack

The next tip for viewing the Venus transit has to do with photography. If you plan on filming or photographing the event through a telescope, now is the time to practice. Do not wait until just a few days before the event to be sure your video equipment is working properly – or that your camera is prepared. Start now by taking practice pictures of the Sun and make sure you have spare batteries or a power supply on hand for the day of the event. Nothing is more disappointing than being ready to photograph an astronomical event and having your equipment fail at the last second. It’s always wise to have a back-up option… such as a cell phone camera, spare pocket camera, or even a camcorder handy just in case. All of these will work afocally. If you practice in advance, you’ll find you can take quite satisfactory photos by just holding the camera to a properly filtered telescope eyepiece.

The last tip for viewing the Venus transit is time. Make sure well in advance of exactly what time the transit starts in your area! The local transit times page by Steven van Roode and Francois Mignard is an excellent resource. But don’t forget… the times are given on an astronomical standard – Universal Time. If you are unsure of how to convert, try the Time Zone Converter to assist you.

The clock is ticking… Be ready!

The Mystery of Venus’ Ashen Light

Venus imaged by Magellan Image Credit: NASA/JPL

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May is the best time to try and spot one of the most enduring unsolved mysteries in our Solar System. Ashen Light is a faint glow allegedly seen on the unlit portion of Venus, during its crescent phase, similar to the earthshine often observed on the Moon, though not as bright. It is more commonly observed while Venus occupies the evening sky, as now, than when it is in the morning sky. But no one really knows for sure what causes it.

So what’s the history of our knowledge about this enigmatic glow?

The phenomenon was first noted in 1643, by Italian astronomer Giovanni Battista Riccioli. Though many notable astronomers have reported sightings in the 369 years since, including Sir William Herschel and more recently, Sir Patrick Moore, many others have failed to see the effect, leading to claims that it is due to nothing more than observer error, an illusion, atmospheric effect or equipment malfunction. Things are not helped by the fact that nobody has managed to capture an image of Ashen Light, yet.

As the month progresses, Venus nears the Sun, ready for its transit on June 5th to 6th and the planet’s crescent phase will increase in diameter during the month, from 37 arcseconds to 56 arcseconds. The best option for amateur astronomers hoping to catch a fleeting glimpse is to use an occulting bar to block the bright crescent, making any glow present on the unlit portion of Venus, more visible.

There is much controversy and many theories as to the cause of Ashen Light. The Keck 1 telescope on Hawaii reported seeing a subtle green glow and suggested it could be produced as ultraviolet light from the Sun splits molecules of carbon dioxide, known to be common in Venus’ atmosphere, into carbon monoxide and oxygen, but the green light emitted as oxygen recombines to form O2 is thought too faint to explain the effect. Another more likely theory is that multiple lightning strikes are illuminating Venus’ skies. Though the Cassini spacecraft flew by Venus twice on it’s voyage to Saturn and failed to detect the high frequency radio noise we associate with thunderstorms on Earth, in 2007 Venus Express did detect low frequency ‘whistler waves’ that can also result from lightning. It could also be the Venusian equivalent of aurorae.

By far the most bizarre theory, and my personal favourite, was proposed in the early 19th century by the Bavarian astronomer Franz von Gruithuisen, who suggested that Ashen Light was the result of fires lit to clear land for farming on Venus, or to celebrate the coronation of a new Venusian Emperor!

For further reading, a paper on Ashen Light by C. T. Russell and J. L. Phillips

Great ISS Sightings – All Nights this Week of April 9

ISS crossing the evening sky at about 8:40 PM EDT on April 8, 2012 in New Jersey; 25 sec exposure, about 30 degree elevation, looking south. Credit: Ken Kremer.
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    Calling all Skywatching and Space Fans ! This is a great week for observing the International Space Station (ISS), swiftly crossing the evening nighttime sky.

    All this week from Monday thru Saturday, folks all across vast portions of the United States and Canada will be treated to fabulous viewings of the International Space Station. And at very convenient viewing times in the early evening, after dinner and in prime time.

    From Maine to Vancouver, from Ohio to Texas, from Florida to New Mexico – many of you will be in for a rather pleasurable ISS treat.

    Of course the exact viewing times, days, elevations, durations and directions varies greatly depending on your exact location – and clear skies. And the viewing parameters change daily.

    Check out this NASA website for Human Spaceflight Sighting Opportunities. It’s simple. Just plug in your country, state and select a local town. Also check out – Heavens Above.

    This evening, Monday April 9, I shot a few 20 to 30 second exposures as the ISS was speeding past at about a 30 degree elevation. But the best viewings at far higher elevations are yet to come the remainder of this week.

    ISS speeds across evening sky on April 9, 2012. 6 Humans from the US, Russia and the Netherlands are currently living aboard the ISS. Credit: Ken Kremer

    The International Space Station is the brightest manmade object in the night sky and even brighter than Venus depending on orbital mechanics. Only our Sun is brighter. Since Venus is an evening observing target this week, maybe you’ll even be lucky to see the ISS seem to pass close by that hellishly hot planet.

    Have you ever looked at the ISS hurtling overhead ?

    Take some shots and send them to Ken to post here at Universe Today.

    And remember, 6 Humans from the US, Russia and the Netherlands are currently residing aboard the ISS, conducting science research and sending back gorgeous shots of all of us back here on Earth.

Planetary Conjunction Mashup

A triple conjunction between 3 different objects: Venus, The Pleiades and an airplane!! Taken on the 4th Apr 2012, 12:15UT. Credit: Shahrin Ahmad

A Boulder Side of Venus – Conjunctions 2012 from Patrick Cullis on Vimeo.

So far, 2012 has brought us a plethora of planetary conjunctions, with Venus pairing with the Moon, Jupiter and the Pleiades. Not all at the same time, of course, but photographer Patrick Cullis has put them all together in this wonderful timelapse mashup video, which includes the beautiful foreground of the Flatirons of Boulder, CO. “Jupiter and Venus dominated the early days of March, coming within 3 degrees of one another,” writes Patrick. “Then, Venus passed a crescent moon on its way to a meeting with the Seven Sisters, also known as the Pleiades.”

And we’re all waiting for this year’s big conjunction on June 5 or 6, 2012, depending on your location, then the tiny disk of Venus will glide across the face of the Sun. That won’t happen again until 2117.

To complete our conjunction mashup, we’ve got a really unique image, below, of a triple conjunction between 3 different objects, Venus, The Pleiades and an airplane taken on April 4, sent to us by Shahrin Ahmad in Malaysia, PLUS, a wonderful new poem by space’s poet laureate, Stuart Atkinson, about his experiences viewing the recent conjunctions. It’s a must read for any amateur astronomer, putting to words the joys — and disappointments — of lifting your eyes to the heavens!

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CONJUNCTION

By Stuart Atkinson

For weeks I watched them drift towards each other,
Approaching shyly, slyly; two would-be lovers
From a Jane Austen dance, casting furtive glances
Across the ballroom of the golden twilight,
Eyes for no-one else as nightfall drew near.
Venus – lovely and lantern-bright, out-shining
Every other dancer on the floor; Jupiter – fainter
By far but still beaming with a noble light,
Stalking his pretty planetary prey…

The first time I saw them they were still
A third-of-the-sky apart,
But each blazing Turner sunset brought them closer yet,
Each day’s end a little better-placed to gaze
Upon each other’s radiant face,
And a million Earthbound eyes looked on, amazed
To see two such fine celestial jewels
Coming together in the sky.
Some sought out a sheltered, grassy place
Of peace and dark to watch the twin sparks’
Close approach in groups; others stood alone
In overgrown gardens or on concrete roofs,
Marvelling at the view from their light-polluted
Homes, wondering what they would see if only
They could escape the Bright and find a place
Without the blinding security lights’ flares
And streetlights’ orange glare…

Of course, I missed the breathless climax
Of their brief encounter. For half a dozen days
Either side of that ringed-in-red date
My sky was thick with cloud fat and foul,
A star- and planet-hiding shroud draped o’er
The Auld Grey Town that was not pulled away
Until the planet parade had passed by,
And the next time I looked to the west
The best view had come and gone:
Unseen by me, Venus and Jupiter had chastely
Touched fingers then parted, leaving
The lovesick gas giant fading, falling
Forlornly towards the rooftops and trees
While the Goddess of Love soared higher,
Growing ever-brighter as she climbed…

Cheated? Yes. But I have fine memories
Of some magical nights, and a hundred photographs,
Taken from the shores of moonlit, duck-dotted lakes
And crumbling castle walls. Sometimes in company,
More usually alone I stood and watched those distant
Worlds waltzing across the western sky,
My so-often-now world weary eyes
Suddenly wide again with wonder at the beauty of it all,
Listening to them calling “Look at us! See
How gloriously we shine above your sleepy little town…!”

…Far apart now, their dusky dalliance a thing of the past,
Venus and Jupiter are just bright stars once more;
The night sky’s restless showbiz spotlight has swept on,
Picking out Saturn, Mars and a waning Moon,
The Great Conjunction relegated
To Celestial Celebrity Has Been history.

Which is how it should be.

The Earth turns, and turns, and turns, setting a universe
Of stars and planets wheeling around pale Polaris,
Lovely and sentinel-still,
While the Milky Way floats serenely
Through her snow-globe of glitter-flake galaxies,
The prickling breeze of a billion billion suns’ solar winds
Blowing on the faces of the few evolved apes
Brave enough to lift their eyes from the grey
Landscapes of their everyday lives and catch
A fleeting glimpse of beauty in the Great Beyond…

© Stuart Atkinson 2012

Astrophotos from Around the World of the Venus-Pleiades Conjunction

Venus at The Seven Sisters, M45 Pleiades on 04-04-2012. Credit and copyright John Chumack.

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The past several evenings, Venus has been snuggling up to one of the most famous star clusters, the Pleiades. Universe Today readers have taken some beautiful images of that event, and they have generously shared them with us. Above is John Chumack’s stunning view from Ohio in the US; see below for more images from around the world!

The Pleiades, also known at the Seven Sisters, is a beautiful bright blue open star cluster 440 light years from Earth. Only once every eight years does this conjunction take place.


Venus within the Pleiades on April 4, 2012, as seen from New Jersey in the US. Credit and copyright John Anton.

John Anton took this pretty image from New Jersey in the US. “It was a beautiful sight,” he said.

Astronomers say that the relative tightness of the cluster indicates this is a young group of stars, and the member stars were formed about 100 million years ago and will probably travel together through space as a bound cluster for another 250 million years before the gravity of the Milky Way breaks up the cluster into individual field stars.

Venus and the Pleiades from San Diego, USA. Credit: Paul Miller
Venus and the Pleiades from the UK. Credit: Dave Liddicott.

“An old SLR 70-210mm zoom lens on my DMC-G10. 5 second exposure, 1600 ISO. Tree illuminated partly by a neighbours light and partly by the built in flash on the camera,” says Dave Liddicott.

The view of Venus and the Pleiades from Norway. Credit: Sirrka Stephens

Sirrka Stephens from Norway took her image using a Panasonic Lumix DMC-F62, Leica 35mm, 30 sec., f/2.8, ISO 80, rotated to the left.

The Venus-Pleiades conjunction from Lebanon.Credit: Space Weed

Space Weed” from Beirut, Lebanon took this image on April 3, 2012. “2 second exposure, ISO 1600, f 5.9, Stack of 40 images and 18 dark frames, Level correction in Photoshop,” Space Weed reports.

Venus shines brilliantly as it passies by the Pleiades star cluster on April 2, 2012. Credit: Tavi Greiner.

Tavi Greiner on the east coast of the US took this lovely image on April 2, 2012.

Venus and the Pleiades on April 3, 2012. Credit: Austin Russie

Another beautiful view from Austin Russie. “A luminous Venus passes directly between Earth and an elusive cluster of stars known as the Pleiades,” he says.

A double exposure, showing how Venus shifted in two hours' time. Credit: L. Laveder - TWAN

Laurent Laveder from France sent in this unusual image showing the shifting of Venus in the Pleiades in two hours’ time.

Image of the conjunction between Venus and M45 Pleiades in the middle of the trees, taken in Fonte-de-Telha, a small pine forest in Portugal. Credit: Miguel Claro

The final image is by Miguel Claro from Portugal, who can be seen enjoying the stars with binoculars “in a peaceful moment,” he said.

There are more images on UT’s Flick page, so check them out!

Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Editor’s note: Apologies for the irregular formatting of this article — we’re working to fix it!

Watch Live Webcast of Venus-Pleiades Conjunction April 4, 2012

Venus on April 3, 2012, when it last passed over the Seven Sisters cluster. Credit: Bob King

There’s a nice meetup in the heavens tonight: bright Venus is snuggling up to one of the most famous star clusters, the Pleiades. The Slooh Space Camera is broadcasting a live, real-time feed of the most famous star cluster in the heavens, the Pleiades, meeting up with our nearest and brightest planetary neighbor, Venus. Slooh’s coverage will begin on Wednesday, April 4th starting at 1:30 PM PDT / 4:30 PM EDT / 20:30 UT. (This was originally scheduled for April 3rd, but was rescheduled due to high humidity at Canary Islands observatory off the coast of Africa.) The broadcast can be watched here, or accessed at Slooh’s homepage or by visiting Slooh’s G+ page, where you will be able to see the panel interact live via G+ Hangouts On Air.

If skies are clear, you can see the conjunction for yourself by looking toward the west in the constellation Taurus, after sunset, using binoculars. If you can get images of the event, we’ll post views of them. Share them on Universe Today’s Flickr page.

Continue reading “Watch Live Webcast of Venus-Pleiades Conjunction April 4, 2012”